The invention relates generally to pressure sensors, and more particularly to a pressure sensor for measuring static and dynamic pressures at high temperatures.
Pressure sensors are used in a wide range of industrial and consumer applications. Pressures of many different magnitudes may be measured using various types of pressure sensors, such as Bourdon-tube type pressure sensors and diaphragm-based pressure sensors. Several variations of the diaphragm-based pressure sensor have been utilized to measure different ranges of pressure, such as by utilizing cantilever-based pressure sensors, optically read pressure sensors and the like.
Both static and dynamic pressure sensing techniques have been developed for specific pressure sensing applications. Attempts have been made to utilize static pressure sensors at high frequencies in an effort to leverage desirable static sensor properties like high sensitivity, linearity, low response time, high stability, high reliability, longer lifetime and the like. Static pressure sensors, however, typically fail to retain one or more of the aforementioned properties when measuring a pressure that tends to change at a relatively high frequency.
Conversely, dynamic pressure sensors may not be suitable at static pressures because desirable properties such as high sensitivity, linearity, fast response, and reliability may not be achievable by the dynamic pressure sensor at low frequencies. Furthermore, at high temperatures, the elasticity of the diaphragm membrane may be diminished. This may make the diaphragm brittle, thereby reducing the reliable lifetime of the pressure sensor and sensitivity.
Attempts also have been made to combine both types of pressure sensors in a single package. These sensors have separate sensing units for static and dynamic pressure ranges hardwired together in a single package. However, such attempts have not been successful because of slower response and noise interference.
It would therefore be desirable to develop a pressure sensor that can be used in both static and dynamic pressure ranges at high temperatures.